I am new to hibernate.When i'm trying to call session.get() method then Nullpointer Exception is occurring.How can i fix it
My pojo class:-
package test; import java.util.*; public class user1 implements java.io.Serializable{ private int id; private String name; private String department; private String password; public user1() {} public user1(int id,String name, String department, String password) { this.id = id; this.name = name; this.department = department; this.password = password; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getDepartment() { return department; } public void setDepartment(String department) { this.department = department; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } } My user1.hbm.xml file:
<?xml version="1.0"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <class name="test.user1" table="users"> <id name="id" column="id" type="int"> </id> <property name="name" column="name" type="string"/> <property name="department" column="department" type="string"/> <property name="password" column="password" type="string"/> </class> </hibernate-mapping> I am calling session.get(user1.class,id) method in my updateUser() function. Nullpointer exception is thrown at runtime.
public class user2 { private static SessionFactory factory; public static void main(String [] args){ try{ factory = new Configuration().configure().buildSessionFactory(); } catch (Throwable ex) { System.err.println("SessionFactory object could not be created"+ex); throw new ExceptionInInitializerError(ex); } user2 User = new user2(); //User.addUser(3,"cc","cse","cc"); //User.showUser(); User.updateUser(Integer.valueOf(3),"dd","cse","dd"); } public void addUser(int id,String name,String department,String password){ Session session = factory.openSession(); Transaction t = null; try{ t = session.beginTransaction(); user1 User1 = new user1(id,name,department,password); session.save(User1); t.commit(); } catch (HibernateException e) { if (t!=null) t.rollback(); e.printStackTrace(); } finally { session.close(); } } public void updateUser(Integer id,String name,String department,String password){ Session session = factory.openSession(); Transaction t = null; try{ user1 user = (user1)session.get(user1.class,id); user.setName(name); user.setDepartment(department); user.setPassword(password); session.update(user); t.commit(); } catch (HibernateException e) { if (t!=null) t.rollback(); e.printStackTrace(); } finally { session.close(); } } } } 
